Ruthie is the affectionate short form of Ruth, a Hebrew name of uncertain origin that is usually explained as "friend" or "companion". The biblical Ruth, the loyal Moabite widow who followed her mother-in-law Naomi, gave the name its reputation for devotion. Ruthie is part of the current taste for vintage nicknames as full names: it entered the US top 1000 in 2023 and has climbed to number 781 in 2025, its best rank so far.